The present invention relates to equipment for approach area monitoring for escalators and travelling walkways for the control of the drive.
In known controls for escalators, the drive is switched off in the case of an unused escalator. When passengers approach the escalator, for example, on passage through a light barrier, a signal is generated and the drive switched on. After elapse of a predetermined period of time, at the earliest after departure of the last passenger from the escalator, the drive is switched off again.
A control system for drives of escalators is shown in the U.S. Pat. No. 1,985,563 in which columns with a light barrier are arranged at the entrance to the escalator. If a passenger passes through the light beam, then the escalator standing in an unused state is switched on.
In the case of the above-described solution, the light barrier is arranged on separate columns and spaced from the escalator. This requires an additional and unneeded material and installation expenditure. Moreover, a passenger is not necessarily guided through the light barrier. A person who does not know the control system and who approaches the stationary escalator from the side can, by going around the light barrier, step onto the escalator without switching it on. This can arouse the disadvantageous impression of a defective or an unreliable escalator.
Moreover, as shown in the European Patent 0 621 225, a display and information device for an escalator is installed in the balustrade. This panel-like device is detachably connected to the balustrade. This device comprises several components, such as light barriers, indicator elements, etc.
A mode of operation as already described above is not possible by this light barrier. If a passenger steps onto the stationary escalator and interrupts the light barrier at the height of the handrail deflection, the drive is thereby switched on. In this case, an unpleasant state, possibly even dangerous and thereby unreasonable for the passenger, arises because the passenger is already standing on the steps of the escalator on start up. Furthermore, in this solution, an additional panel is also necessary in order to accommodate components such as the light barrier. This panel moreover diminishes the visual effect of the balustrade, which possibly consists of glass, and offers practically no protection against vandalism.